Google will sell co-branded tablets by the end of this year, putting more heat on Apple's iPad, says a Wall Street Journal report.

The tablet will be sold directly to consumers through a Google online store, according to the Journal's un-named sources.

Through its $US12.5 billion acquisition of Motorola's mobile business (approved in the US and Europe put not yet China's regulator), Google will soon have the ability to mass manufacture tablets (Motorola already makes the Xoom tablet).

However, Google is expected to work with hardware partners, "including Samsung AsusTeK."

In the smartphone market, Google has made on-again-off-again efforts to promote its own handset, the Nexus One (originally Google branded and contracted by HTC, then subsequently co-branded with Samsung). The Nexus One was originally only available through a Google website.

Analysts say the Nexus One as an attempt to gin up the market for Google's Android mobile software, now used to run most smartphones made by Motorola, Samsung, Sony, LG, Huawei and others.

Once Android pulled ahead of Apple's iPad, Google pulled back on promoting the Nexus One.

Commentators see Google doing the same thing with its branded tablet - pushing it for a while to help establish Android in the market (unlike in smartphones, it still holds minority share in tablets), but still supporting partners who make their own models.